The early signs: stomach, mouth and appetite
Most poisoning cases announce themselves in the gut first. Vomiting — sometimes repeated, sometimes containing recognisable pieces of whatever was eaten — is the commonest opening sign, often alongside drooling far beyond the dog's normal, pawing at the mouth, lip-smacking and obvious nausea. Diarrhoea may follow, sometimes with blood in it, and a dog who normally inhales his food refusing a meal entirely is a sign owners should never shrug off in this context. A sore, swollen or tender belly, restlessness and whining point the same way. None of these signs proves poisoning, because stomach upsets have many causes — but if there is any chance something toxic was within reach, treat the combination as poisoning until a vet tells you otherwise.
The serious signs: nerves, gums and breathing
Some toxins move fast beyond the stomach, and the next tier of signs is an emergency on sight: wobbliness or a drunken gait, trembling or muscle twitching, collapse, and seizures. Pale, white or muddy-grey gums signal trouble with circulation, while very rapid breathing, panting at rest or visibly laboured breathing means the body is struggling. A racing or erratic heartbeat, extreme drowsiness, or a dog who cannot be roused properly all belong in the same urgent category. Certain poisons also work slowly — a dog can seem merely quiet for a day or two and then deteriorate — which is why a known or suspected ingestion deserves a vet call immediately, not a wait to see whether the dramatic signs arrive.
Why minutes matter more than symptoms
Owners understandably want a test: which signs mean it is serious? Poisoning defeats that logic, because the most treatable moment is usually before the serious signs appear, while the substance is still in the stomach or only freshly absorbed. Different toxins also run on different clocks — some act within the hour, others damage organs quietly over days — and from the outside they can look identical in their first phase. So the working rule here is different from most dog care: do not grade the signs, grade the exposure. If you know or strongly suspect he ate something poisonous, the phone call happens now; if you only have suspicious signs, the phone call happens now anyway, and you describe them.
What to do while you get help
Phone your vet, an emergency clinic or an animal poison helpline immediately and say what you think he ate, roughly how much, and when — then follow their instructions exactly. Do not make him sick unless you are specifically told to: some substances burn on the way back up, and vomiting at the wrong moment can be inhaled. Move the remaining substance, plant material or packaging out of reach of every animal in the house, and keep the packet or photograph the label, because the ingredient list is what the vet's plan will be built from. Keep the dog warm, quiet and observed, and note the times signs appear or change while you travel. Having his weight, his health history and the vet's number ready speeds up all of this, which is why they live in his KinsLe Pet Passport — one packet you can read from on the phone and hand over when you arrive at the clinic.